Google Trends (arguably just a proxy metric) seems to imply linear growth for the last five years, though not too much acceleration for the last 12 months: https://trends.google.com/trends/explore?q=%2Fg%2F11cn3w0w9t
Other growth indicators:
- More and more GraphQL conferences (with growing number of attendees), e.g. GraphQL Europe with 300 attendees last year, 500 attendees this year and as the rebranded GraphQL conf is aiming for 1000 attendees next year.
- The GraphQL Foundation that's currently being established (https://medium.com/@leeb/introducing-the-graphql-foundation-...)
- An ever growing list of companies adopting GraphQL (http://graphql.org/users); big companies betting on GraphQL like Facebook, GitHub, Twitter, Airbnb, Shopify, ...
I personally believe that GraphQL is still in its infancy and will become the new API standard over the next few years. I recently wrote an article about my personal top reasons for adopting GraphQL: https://www.prisma.io/blog/top-5-reasons-to-use-graphql-b60c...